1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2012 Regents of the University of California
4 */
5
6 #ifndef _ASM_RISCV_PROCESSOR_H
7 #define _ASM_RISCV_PROCESSOR_H
8
9 #include <linux/const.h>
10 #include <linux/cache.h>
11
12 #include <vdso/processor.h>
13
14 #include <asm/ptrace.h>
15
16 #ifdef CONFIG_64BIT
17 #define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1))
18 #define STACK_TOP_MAX TASK_SIZE
19
20 #define arch_get_mmap_end(addr, len, flags) \
21 ({ \
22 unsigned long mmap_end; \
23 typeof(addr) _addr = (addr); \
24 if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
25 mmap_end = STACK_TOP_MAX; \
26 else if ((_addr) >= VA_USER_SV57) \
27 mmap_end = STACK_TOP_MAX; \
28 else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
29 mmap_end = VA_USER_SV48; \
30 else \
31 mmap_end = VA_USER_SV39; \
32 mmap_end; \
33 })
34
35 #define arch_get_mmap_base(addr, base) \
36 ({ \
37 unsigned long mmap_base; \
38 typeof(addr) _addr = (addr); \
39 typeof(base) _base = (base); \
40 unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \
41 if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
42 mmap_base = (_base); \
43 else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
44 mmap_base = VA_USER_SV57 - rnd_gap; \
45 else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
46 mmap_base = VA_USER_SV48 - rnd_gap; \
47 else \
48 mmap_base = VA_USER_SV39 - rnd_gap; \
49 mmap_base; \
50 })
51
52 #else
53 #define DEFAULT_MAP_WINDOW TASK_SIZE
54 #define STACK_TOP_MAX TASK_SIZE
55 #endif
56 #define STACK_ALIGN 16
57
58 #define STACK_TOP DEFAULT_MAP_WINDOW
59
60 /*
61 * This decides where the kernel will search for a free chunk of vm
62 * space during mmap's.
63 */
64 #ifdef CONFIG_64BIT
65 #define TASK_UNMAPPED_BASE PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3)
66 #else
67 #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
68 #endif
69
70 #ifndef __ASSEMBLY__
71
72 struct task_struct;
73 struct pt_regs;
74
75 /*
76 * We use a flag to track in-kernel Vector context. Currently the flag has the
77 * following meaning:
78 *
79 * - bit 0: indicates whether the in-kernel Vector context is active. The
80 * activation of this state disables the preemption. On a non-RT kernel, it
81 * also disable bh.
82 * - bits 8: is used for tracking preemptible kernel-mode Vector, when
83 * RISCV_ISA_V_PREEMPTIVE is enabled. Calling kernel_vector_begin() does not
84 * disable the preemption if the thread's kernel_vstate.datap is allocated.
85 * Instead, the kernel set this bit field. Then the trap entry/exit code
86 * knows if we are entering/exiting the context that owns preempt_v.
87 * - 0: the task is not using preempt_v
88 * - 1: the task is actively using preempt_v. But whether does the task own
89 * the preempt_v context is decided by bits in RISCV_V_CTX_DEPTH_MASK.
90 * - bit 16-23 are RISCV_V_CTX_DEPTH_MASK, used by context tracking routine
91 * when preempt_v starts:
92 * - 0: the task is actively using, and own preempt_v context.
93 * - non-zero: the task was using preempt_v, but then took a trap within.
94 * Thus, the task does not own preempt_v. Any use of Vector will have to
95 * save preempt_v, if dirty, and fallback to non-preemptible kernel-mode
96 * Vector.
97 * - bit 30: The in-kernel preempt_v context is saved, and requries to be
98 * restored when returning to the context that owns the preempt_v.
99 * - bit 31: The in-kernel preempt_v context is dirty, as signaled by the
100 * trap entry code. Any context switches out-of current task need to save
101 * it to the task's in-kernel V context. Also, any traps nesting on-top-of
102 * preempt_v requesting to use V needs a save.
103 */
104 #define RISCV_V_CTX_DEPTH_MASK 0x00ff0000
105
106 #define RISCV_V_CTX_UNIT_DEPTH 0x00010000
107 #define RISCV_KERNEL_MODE_V 0x00000001
108 #define RISCV_PREEMPT_V 0x00000100
109 #define RISCV_PREEMPT_V_DIRTY 0x80000000
110 #define RISCV_PREEMPT_V_NEED_RESTORE 0x40000000
111
112 /* CPU-specific state of a task */
113 struct thread_struct {
114 /* Callee-saved registers */
115 unsigned long ra;
116 unsigned long sp; /* Kernel mode stack */
117 unsigned long s[12]; /* s[0]: frame pointer */
118 struct __riscv_d_ext_state fstate;
119 unsigned long bad_cause;
120 u32 riscv_v_flags;
121 u32 vstate_ctrl;
122 struct __riscv_v_ext_state vstate;
123 struct __riscv_v_ext_state kernel_vstate;
124 };
125
126 /* Whitelist the fstate from the task_struct for hardened usercopy */
arch_thread_struct_whitelist(unsigned long * offset,unsigned long * size)127 static inline void arch_thread_struct_whitelist(unsigned long *offset,
128 unsigned long *size)
129 {
130 *offset = offsetof(struct thread_struct, fstate);
131 *size = sizeof_field(struct thread_struct, fstate);
132 }
133
134 #define INIT_THREAD { \
135 .sp = sizeof(init_stack) + (long)&init_stack, \
136 }
137
138 #define task_pt_regs(tsk) \
139 ((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE \
140 - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
141
142 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->epc)
143 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
144
145
146 /* Do necessary setup to start up a newly executed thread. */
147 extern void start_thread(struct pt_regs *regs,
148 unsigned long pc, unsigned long sp);
149
150 extern unsigned long __get_wchan(struct task_struct *p);
151
152
wait_for_interrupt(void)153 static inline void wait_for_interrupt(void)
154 {
155 __asm__ __volatile__ ("wfi");
156 }
157
158 struct device_node;
159 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
160 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
161 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
162
163 extern void riscv_fill_hwcap(void);
164 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
165
166 extern unsigned long signal_minsigstksz __ro_after_init;
167
168 #ifdef CONFIG_RISCV_ISA_V
169 /* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */
170 #define RISCV_V_SET_CONTROL(arg) riscv_v_vstate_ctrl_set_current(arg)
171 #define RISCV_V_GET_CONTROL() riscv_v_vstate_ctrl_get_current()
172 extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
173 extern long riscv_v_vstate_ctrl_get_current(void);
174 #endif /* CONFIG_RISCV_ISA_V */
175
176 #endif /* __ASSEMBLY__ */
177
178 #endif /* _ASM_RISCV_PROCESSOR_H */
179